As muscles grow, their fibres pennate more steeply and force per unit of size falls in strength athletes, yet pennation is also how a muscle packs in more fibres: a trade-off, not a fixed ceiling.

In two small trials in young men, 25 g of whey around a two-week training break and 7.5 g a day of leucine during a week in a leg cast did not change the outcome. Strength held through the break regardless; muscle shrank in the cast regardless.

One randomised trial in adults over 65 found gains in knee extensor torque, grip strength and muscle thickness with krill oil. No study read here has measured its effect on strength or size in people who lift.

A 2025 meta-analysis of 19 studies found supersets shortened sessions with similar repetitions, volume load and long-term strength and hypertrophy, at the cost of higher effort, lactate and energy cost.

In a 12-week trial in resistance-trained men, 400 mg a day of oral ATP was linked to +55.3 kg total strength versus +22.4 kg with placebo. A pilot sharing several authors found raised post-exercise blood flow. Striking results, with no independent replication read.

In trained lifters over 8 weeks and untrained adults over 10 weeks, progressing repetitions at a fixed load produced strength and muscle gains similar to progressing the load.

In untrained adults, standing calf raises grew the gastrocnemius more than seated calf raises over 12 weeks, while soleus growth was similar either way. What the evidence does and does not show.

Pyramid sets built strength in the trials we read, and muscle in older women, but we found no evidence that they beat simpler loading, and in trained men heavier loading produced larger strength gains. Here is the evidence and its limits.

Protein synthesis after a first workout did not correlate with 16 weeks of growth in untrained men, and in another cohort acute rises in growth hormone, free testosterone and IGF-1 did not predict lean mass or strength gains. Short-term markers can mislead.

A systematic review of 12 studies found an ergogenic effect of nitrate on strength in six, with the best results after an acute dose of at least 400 mg taken 2 to 2.5 hours before exercise. A 2023 meta-analysis found small improvements in repetitions to failure and mean power. Neither abstract reports a muscle growth result.

A popular idea holds that light, high-rep sets build type I fibres and heavy sets build type II. A meta-analysis of sets taken to failure found no significant difference between low and high loads for either fibre type, with very wide uncertainty.

In 11 male bodybuilders measured the day before and on contest day, intracellular water rose and extracellular water fell, consistent with fluid moving into the cells during the final day of peak week.

A synthesis of 20 published studies describes competitive bodybuilding as a journey of self-discovery, new identity and control, with conditional and unconditional social support. A survey of 984 men found competitors differed little psychologically from recreational lifters, apart from higher use of appearance- and performance-enhancing drugs.

Fat-free mass index scales lean mass to height and is often read as a natural ceiling. Here is what the benchmark studies in male and female athletes actually measured, and why a benchmark is not the same as a forecast.

Across 111 studies in healthy men, resistance training added about 1.5 kg of muscle mass on average (95% CI 1.30 to 1.76 kg), and in a small flywheel study quadriceps growth was detectable after 20 days.

In 38 resistance-trained men on a six-week diet, 5 sets per exercise were neither better nor worse than 3 sets per exercise for maintaining lean mass or muscle thickness.

Buffered creatine did not raise muscle creatine, strength or lean mass more than monohydrate, and creatine ethyl ester was less effective at raising serum and muscle creatine. A review found little to no evidence that newer forms are more effective or safer.

In a 6-week randomised, double-blind trial in untrained men, capsiate with resistance training increased fat-free mass, mostly as total body water, and improved bench press gains more than placebo, with no effect on lower-body strength or inflammation. Two small acute trials suggest single-session benefits.

In a small study of untrained men, changes in vastus lateralis fibre size, pennation angle and fascicle length did not collectively predict changes in whole-muscle cross-sectional area. Different measures of hypertrophy often tell different stories.

Blood flow restriction lets lifters train with light loads. In a small trial in national-level powerlifters, blood flow restriction front squats produced greater quadriceps growth than conventional front squats over 6.5 weeks, but direct evidence in trained lifters remains thin.